Answer 1

When you write a method you can make it with parameter or without parameter. You define variables in parantheses after the method. As you can se below

// with parameters

int calculateAge(int BornYear, int CurrentYear);
int age = CurrentYear-BornYear;
System.out.println("Your age is :" + age);

//without parameters

int BornYear=2000;
int CurrentYear=2016;

int calculateAge();
int age = CurrentYear-BornYear;
System.out.println("Your age is :" + age);